# 🐧 Top Linux Commands Every DevOps Beginner Must Know (With Examples) ## πŸ“Œ Introduction If you are starting your journey in **Linux, DevOps, or Cloud Computing**, Linux commands are not optional β€” they are **mandatory**. Most production servers run on **Linux**, and as a DevOps engineer, you’ll interact with servers daily for: * Deployment * Monitoring * Debugging * Automation In this post, I’m sharing a **structured Linux commands cheat sheet (basic + advanced)** with **clear explanations and real examples**, especially useful for **beginners and DevOps learners**. > πŸ‘‹ If you found this article helpful and want to follow my **DevOps learning journey**, > connect with me on **LinkedIn** πŸ‘‰ [RamuChelloju](https://www.linkedin.com/in/ramuchelloju/) --- ## 🧱 1. Basic Linux Commands These commands are used **every day** on any Linux system. ### πŸ”Ή List files and directories ```plaintext ls ls -l ls -a ``` ### πŸ”Ή Change directory ```plaintext cd /var/log cd .. ``` ### πŸ”Ή Show current path ```plaintext pwd ``` ### πŸ”Ή Create and remove directories ```plaintext mkdir app rmdir app ``` ### πŸ”Ή Copy and move files ```plaintext cp file1 file2 cp -r dir1 dir2 mv oldname newname ``` ### πŸ”Ή Create empty file ```plaintext touch test.txt ``` --- ## πŸ“‚ 2. File Operations Used to **read, search, compress, and manage files**. ### πŸ”Ή View file content ```plaintext cat file.txt less largefile.log ``` ### πŸ”Ή Search inside files ```plaintext grep "error" app.log ``` ### πŸ”Ή Archive and compress ```plaintext tar -cvf backup.tar folder/ zip files.zip file1 file2 unzip files.zip ``` ### πŸ”Ή Change permissions and ownership ```plaintext chmod 755 script.sh chown user:group file.txt ``` --- ## βš™οΈ 3. Process & System Monitoring Helps you understand **what is running on the server**. ### πŸ”Ή View running processes ```plaintext ps aux ``` ### πŸ”Ή Live system usage ```plaintext top htop ``` ### πŸ”Ή Run process after logout ```plaintext nohup python app.py & ``` ### πŸ”Ή Process tree ```plaintext pstree ``` ### πŸ”Ή View system logs ```plaintext journalctl journalctl -u nginx ``` --- ## πŸ’½ 4. Disk & Memory Commands Used heavily during **production issues**. ### πŸ”Ή Disk usage ```plaintext df -h du -sh /var/log ``` ### πŸ”Ή Memory usage ```plaintext free -h ``` ### πŸ”Ή Block devices ```plaintext lsblk ``` ### πŸ”Ή Mount and unmount ```plaintext mount /dev/xvdf /data umount /data ``` ### πŸ”Ή Sync files ```plaintext rsync -av source/ destination/ ``` --- ## 🌐 5. Networking Commands Used for **server access and debugging**. ### πŸ”Ή Check connectivity ```plaintext ping google.com ``` ### πŸ”Ή Test APIs and URLs ```plaintext curl https://example.com ``` ### πŸ”Ή Download files ```plaintext wget https://example.com/file.zip ``` ### πŸ”Ή Connect to remote server ```plaintext ssh -i key.pem user@server_ip ``` ### πŸ”Ή Copy files between servers ```plaintext scp file.txt user@server:/path ``` --- ## πŸ” 6. Permissions & Ownership (Very Important) Most Linux issues happen due to **wrong permissions**. ### πŸ”Ή File permissions ```plaintext chmod 644 file.txt chmod 755 script.sh ``` ### πŸ”Ή Change owner ```plaintext chown ec2-user:ec2-user file.txt ``` ### πŸ”Ή Sudo access ```plaintext sudo command ``` ### πŸ”Ή Edit sudoers safely ```plaintext visudo ``` --- ## πŸš€ How DevOps Engineers Use These Commands As a DevOps engineer, you’ll use Linux commands to: * Debug production issues * Check server health * Deploy applications * Automate tasks using shell scripts * Manage cloud servers (AWS EC2, GCP, Azure) πŸ‘‰ **Strong Linux basics = Strong DevOps career** --- ## 🧠 Learning Tips for Beginners * Practice daily (don’t just read) * Break things and fix them * Focus on **understanding**, not memorizing * Combine Linux with Git, Docker, and Cloud --- ## βœ… Conclusion Linux commands are the **foundation** for DevOps, Cloud, and SRE roles. Once you master these basics, learning tools like **Docker, Kubernetes, Jenkins, and Terraform** becomes much easier. If you are a beginner β€” **start slow, stay consistent, and practice daily**.